Alternating current vertical welder



Dec. 28, 1948. E. A. HOBART Er AL ALTERNATING CURRENT VERTICAL WELDER "Filed Feb. 11, 1947 $5 Sheets-Sheet 1 m AM we m HF a WM m mu 1 A mm Eflm Dec. 28,1948. E. A. HOBART ET AL 2,457,372

ALTERNATING CURRENT VERTICAL WEI-DER Filed Feb. 11, 1947 3 Sheets-Sheet 2 FIG.-3 3e NTO I B RT 8 F A ATTORNEY E. A. HOBART ET AL ALTERNATING CURRENT VERTICAL vmmmn Dec. 28, 1948.

Filed Feb. 11, 19.47

3 Sheets-Sheet 3 DWARD gysssu :7

VENTORS ATTORNEYS Patented Dec. 1948 oFFlcEI ALTERNATING CURRENT VERTICAL WELDER Edward A. Hobart and Russell '1'. Flora, Ohio, assignors to The Hobart Brothers pany, Troy, Ohio, a corporation of Ohio r y. Corn- Application February 11, 1947, Serial No. 727,830 (Cl. 111-119) 3 Claims. 1

This invention pertains to improvements in controls for welding transformers.

More particularly, this invention pertains to a method of adapting a uniformly scaled dial, for indicating the number of amperes being produced in a welding apparatus, to a welding transformer in which the rate that the amperes are iven off is not uniform but one that varies according to the position of the transformer coils.

In welding transformers, the'amperage varies according to the proximity of the primary and secondary coils. When these coils are intheir closest relationship, the output of amperes is highest. As the primary coil is moved away from the secondary coil, the quantity of amperes produced decreases at a rapid rate at first, but at a slower rate as the coils are moved farther apart. This change in rate of amperes produced would ordinarily require that the dial used in connection with the welding transformer to indicate the amperes being produced at any giventime would necessarily have to be one incorporating a graduated scale in order to compensate for this changing rate.

Accordingly, an object of this invention'isto incorporate, in connection with a welding transformer, a dial capable of using a standard, uniformly graduated scale to indicate the number of amperes being produced in the welding apparatus.

the possibility of mistakes occurring in welding operations caused by incorrect dial readings, by making possible the use of an easily read, uniformly scaled dial instead of the more difiicultly read, variably scaled dial.

Further features and advantages of this" invention will appear from a detailed description of the drawings in which:

Figure 1 is a side view of a welding transformer incorporating the features of this invention.

Figure 2 is a. front view of the upper portion of the welding transformer shown by the line 2--2 of Figure 1.

Figure 3 is a sectional and descriptive view shown by the line 3-3 of Figures 1 and 4.

Figure 4 is a top view of the welding transformer shown by the line 4 4 of Figure 3.

Figure 5 is a side sectional and descriptive view of a welding transformer incorporating an alternative arrangement of this invention.

Figure 6 is a top view of the welding transformer and alternative arrangement shown by the line 6-6 of Figure 5.

Referring particularly to Figure 3, the welding and I3. The base of the front angle iron of the pair of angle irons Another object of this invention is to decrease i2 is connected by a cross member I4 to the base of the front angle iron of the pair l3. The bases of the rear angle iron or each pair or angle irons l2 and |3 are similarly connected. The cross members H are securely bolted at l5. The tops of the pairs of frame members l2 and I3 are similarly connected by cross members l6, Figure 4. The cross members l6 are held together by the bolts ll.

A core l8, referring again to Figure 3, is positloned between the pair of angle irons l2, the cross members l3 (note Figure 4), a strip l3, and the cross members l4. A core 20 is similarly positioned between the pair of angle irons I3, the cross members It (note Figure 4), a strip Illa, and the cross members H. The secondary coil 2| is suitably fixed on the cross members H by the clampingbolts 22. The primary coil 23 is guided for vertical movement on the strips I3 and 3a of the core members l3 and 20. This movement is effected by a screw 24 and nut 25 fixed to the coil 23. The cores l3 and 20 both pass through the transformer coils 2| and 23. The primary coil 23 may be moved up or down on the screw 24 by movement of the knob 23 fixed to the cap 21, which cap is suitably fastened by a nut 24a to the screw 24.

An angle iron functioning as an arm 23 is fixed to the primary coil 23 by the bolt and nut arrangement 23. A roller 30 is journaled on a pin 33a carried in the arm 28.- An arm 3| fixed to a pulley 32 is placed on Figure 4, so that the screw 24 passes through the center of the pulley 32 in such a manner that the movements of the screw 24 and of the pulley 32 are independent of each other. To the end of the arm 3| is attached a semi-circular metal band 33. To this band 33 is secured a card 34 on which is printed a uniformly graduated scale. A bolt 35 is fixed to the arm 3|. A rod 33 is fastened to one of the cross members IS. A torsion coil spring 31 is placed around the screw 24 but independent of it. One end of the spring 31 is hooked around the fixed rod 36 and the other end of the spring 31 is placed against the bolt 35, fixed on the arm 3|, so that the spring 31 tends to normally turn the arm 3| in a is a pair of angle the cross members l3,

3 clockwise direction, Figure 4. Also fixed to the cross members i3 are eyelets 33 by which the whole welding apparatus may be lifted.

A cable 38, referring again to Figure 3, is fixed to the pulley 32 and wrapped around it, the other end of the cable 33 is attached by hook arrangement 40 to the lever ll. Lever ll is pivoted to the front member of the pair of frame members It by the pin means 42. The roller 30 of the arm 23 contacts the lever surface Ma.

A cover' 42. Figure 2, is placed around the apparatus. In the cover 42 is a window 43 having a fixed indicator line 44 through its center. Through the window 43 may be seen the card 33 on which the uniform scale is printed.

In operation, referring again to Figure 3, rotating the cap 21 by the knob 23 turns the screw 24 so that the primary coil 23 is either raised or lowered as desired. When the primary coil 23 moves upward, the arm 23 with attached roller ll actsagainst the surface a of the pivoted lever ll. This swinging movement of the lever ll exerts a pull on the cable 39 which actuates the pulley 32 so as to turn the arm 3! and uniformly scaled card 34 in a counterclockwise direction, opposed to the coil spring 31. When the primary coil 23 is in closest relationship to the secondary coil 2|, the output of amperes is greatest.

As the primary coil 23 moves up on the screw 24 away from the secondary coil 2i, the quantity of amperes produced falls ofl at a rate which is initially great but which rate of fall-off diminishes as the coils become farther apart. A short movement of the primary coil 23 when it is close to the secondary coil 2| will result in the pulley 32 (and arm 3i and card in being turnedv through a greater distance than will the same amount of movement of the primary cell 23 when it is farther from the secondary coil 2i. v

Thus equal movements of the primary coil 23 will cause varying movements of the card 34, depending on the distance relationship between the primary coil 23 and secondary coil 2i.

Thus, when the primary and secondary coils are close together, a small movement of the pri.

mary coil 23 away from the. secondary coil 2i will result not only in a large drop in the rate of amperes being produced, but also in a large movement of the card 34 to compensate for this. Similarly, when the coils are further apart, a small movement, equal to that mentioned above, of the primary coil 23 away from the secondary coil 2i will result in only a small drop in the rate of amperes produced but, compensating for this, it will also result in only a small movement of the card 34. Thus, a uniformly graduated scale may be used on the card 34 to indicate the varying quantity of amperes being produced in the welding transformer since these variations in their rate of production are automatically taken care of by the above described mechanism.

In the alternative arrangement, Figures 5 and 6, the lever arrangement above has been replaced by the use of a cam or eccentrically-shaped pulley. The welding transformer itself is constructed similarly to that just described.

' To the primary coil 23 is fixed an arm 35. A cable 33 is fastened to the end of this arm 45. The cable 33 passes over an idler pulley 45 which is fixed to an arm 41 fixed on the cross member ii. The cable 33 is attached to and wrapped around a cam or eccentrically-shaped pulley 48 secured to the arm 3|. A torsion coil spring 31 placed around the screw 2 and resting on the cross members I! has its ends secured to the rod 33, fixed to whilethe cross members I3, and the rod 43, attached to the cam or eccentrically-shaped pulley II. The pulls exerted on the cam 43 and arm 3| by the spring 31 and cable 33 are in opposition to one another.

The necessary variations in the distance that the card 34 must move in order to indicate the amperes being produced by the welding apparatus are caused by this cam arrangement. As the primary coil 23 is moved away from the secondary coil 2|, the cam or eccentrically-shaped pulley moves at first through great distances and then. as the coils become farther apart, through shorter distances. Thus, this arrangement also provides a method for using a uniformly scaled card to indicate the amperes produced in a welding apparatus in which the rate of amperes given off is not uniform but one which varies, depending on the distance relationship of the transformer coils. Again this changing rate is compensated for by the mechanism, in this case the cam arrangement, rather than by varying the 'graduations of the scale used on the dial card.

to be secured by United States Letters Patent 1. In a welding transformer having a pair of relatively movable transformer coils, adjusting means for relatively moving said coils, a uniformly graduated indicator dial showing the output of said transformer, means for actuating said dial to variably spaced positions during the relative movement between said coils to regularly spaced positions comprising a lever means, and means for regulating said last mentioned lever means so that said dial is moved at rates which vary according to the relative positions of said coils comprising a contacting device moved by said adjusting means engaging said lever and moved longitudinally thereof upon relative movement of said coils.

2. In a welding transformer having a pair of relatively movable transformer coils, a uniformly graduated indicator dial showing the output of said transformer, means for moving said coils relative to one another so as to vary the output of said transformer, and a lever and pulley arrangement for variably positioning said indicator dial during the regular relative positioning of said coils so as to indicate the output of said transformer for all positions of said coils including means for pivotally supporting one end of said lever, a cable interconnected between the other end of said lever and said pulley, a lever actuating contact, member movable longitudinally of said lever radially of the axis of said .pivotal support, and means for longitudinally I 6 and fixed to a pulley J'ournaled in said frame, a REFERENCES CITED swinging lever pivoted on said frame at one end and hooked to said pulley by a cable attached g g fi g gt gg are of record in h to its other end, means including a lever contactp ing device movable longitudinally of said lever 5 UNITED STATES PATENTS between said pivot and said cable attachment Number N points, and a support for saidcontacting device 516,847 g' g Mar 9 6 moved by said adjusting mechanism for actuat- 497,180 Gates 1898 ing said swinging lever during the relative move- 2438202 Bums Man 1948 ment of said coils so as to move'said dial to pre- 10 determined variable positions for uniform relative positions or said coils.

EDWARD A. HOBART. RUSSELL T. FLORA. 

